共查询到20条相似文献,搜索用时 15 毫秒
1.
本实验制作不同程度心肌缺血的动物模型,以声处理5%人血白蛋白为超声造影剂进行心肌灌注造影,探讨MCE时间-强度曲线各指标与心肌缺血程度间的关系。结果表明:心肌显影的峰值强度和曲线下面积均与缺血程度呈显著负相关(相关系数分别为r=-0.98,P值<0.005;r=-0.94,P值<0.05),且能区分轻度、中度和重度三种程度的心肌缺血;而三项时间指标与心肌缺血程度间未发现显著性差异。本实验的初步结果表明,MCE是一项活体评估局部心肌血流灌注的有效方法。 相似文献
2.
目的:观察能量多普勒造影技术(PCI)行静脉心肌声学造影(MCE)的效果。方法:利用PCI技术观察6例非特异性胸痛患者及3例陈旧性心肌梗塞患者的经静脉心肌声学造影效果。其中,心肌梗塞患者在MCE后一周内行核素检查。结果:6例非特异性胸痛患者均未见节段室壁运动异常,在声学造影剂注射后见全部心肌组织均匀显影 3例陈旧性心肌梗塞患者则见梗塞相应部位室壁运动异常,且声学造影检查发现该部位多普勒能量信号缺失 相似文献
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宫腔双氧水声学造影在诊断子宫腺肌病的应用 总被引:8,自引:0,他引:8
B超常规检查合并用3%双氧水宫腔声学造影法观察了29例子宫腺肌病患者(术后证实20例腺肌症。9例腺肌瘤),并用10例单纯子宫肌瘤及10例正常生育年龄妇女作对照。结果表明24例腺肌病病人宫腔声学造影后呈阳性结果。阳性率82.76%.即宫壁有造影剂弥散。呈分枝状或斑点状强回声区;5例呈阴性结果。子宫肌瘤及正常组均为阴性结果。本文讨论了发生宫壁双氧水弥散及弥散程度的原因,并认为宫腔双氧水声学造影对协助诊断子宫腺肌病有很大帮助。 相似文献
4.
Pancreatic splenosis is a very rare condition whose features on contrast-enhanced ultrasound (CEUS) have not, to our knowledge, been previously reported. We present the imaging findings in a case of pancreatic splenosis, in which a confident diagnosis was achieved with the use of CEUS and confirmed by a labeled heat denatured red cell scan. Accumulation of ultrasound contrast microbubbles in splenic tissue can be readily visualized on late-phase CEUS and this technique has already been used to confirm the nature of intrapancreatic accessory spleens. This case shows that it can also confirm the diagnosis of splenosis. 相似文献
5.
《Journal of Medical Imaging and Radiation Sciences》2014,45(3):327-329
Extravasation of ionic and nonionic contrast materials is a well-recognized complication of contrast-enhanced imaging studies. Complications vary from minimal swelling to severe skin and subcutaneous ulceration, necrosis, and compartment syndrome. We report a case of Omnipaque (iohexol) extravasation in a 50-year-old man with erythema, blistering, and compartment syndrome who was treated medically but was not cured. Using gray scale ultrasonography, we determined the characteristics of the lesion, its distance from the skin, and its proximity to the vessels. We then determined the depth of the lesion, and then inserted the tip of the needle into the lesion. We also used ultrasonography in locations where extravasation was near an artery. After aspiration, the diameter of the lesion decreased significantly. The patient was cured by ultrasonography-guided aspiration from the extravasated site. 相似文献
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Haruka Kobayashi Shintaro Beppu Sjsum Fuminobu Ishikura Fjsum Hiroaki Ueda Keisuke Matsushita Yasushi Kashiwagi Sachiko Yagura Toshiaki Hamada 《Journal of Medical Ultrasonics》2001,28(3):103-109
Background Although Optison (FS-69) is commercially available in the United States, the optimal setup of ultrasonic equipment for myocardial
contrast echocardiography has yet to be elucidated. Here we examine the optimal setting for adequate opacification of the
myocardium.
Method Optison (0.1 ml) was administered intravenously during recording of the short axis view of the left ventricle using the Toshiba
prototype echocardiographic system in 11 open-chest beagledogs. Myocardial opacification was evaluated by calculating the
baseline-subtracted peak video intensity (256 gray scale) at four regions of the left ventricular wall: the anterior, lateral,
posterior, and septal walls. We examined the fundamental (3.75 MHz) and second harmonic (2.5/5.0 MHz) imaging during both
continuous and intermittent (one pulse per cardiac cycle) mode. Acoustic power (AP) decreased in steps of 1.5 dB from maximal
mechanical index (1.4). We also examined the effect of the distance between and the heart by placing an ultrasonic spacer
with a width of 1 cm or 3 cm.
Results Myocardial opacification was hardly, recognized by the continuous mode; however, the intermittent mode provided sufficient
opacification in either the fundamental or harmonic mode. Excessive acoustic power did not improve myocardial opacification.
The influence of high acoustic power was significant in the field near the transducer.
Conclusion The left ventricular myocardium is clearly opacified by venous administration, of Optison when the mechanical settings of
the ultrasonic equipment are appropriate. 相似文献
8.
Purpose The aim of this study was to establish the relation between observed ultrasonographic (US) images produced with a galactose-based contrast agent and histologic characteristics of small hepatocellular carcinomas (HCCs).Materials and methods A total of 64 nodules in 64 patients, 22 well differentiated and 42 moderately differentiated with a histologically proven HCC, smaller than 3.0cm in diameter and who had undergone hepatectomy were consecutively examined by contrast-enhanced US using a galactose-based contrast agent. Perfusion images were acquired by intermittent high-intensity, harmonic power Doppler sonography using a high pulse-repetition frequency and high-pass filter setting. Perfusion images of the arterial and late phases were classified into several patterns and compared with the histologic findings obtained from resected specimens.Results Most of the well- and moderately differentiated resected HCCs showed hyperechoic change during the arterial phase. However, 13 (59%) of the well-differentiated HCCs showed isoechoic change and 27 (64%) of the moderately differentiated HCCs showed hypoechoic change during the late phase. The difference is statistically significant (P < 0.0001). In a comparison of microscopic portal invasion (vp) of HCCs using enhanced US patterns, both vp(–) and vp(+) groups showed a high incidence of the hypervascular pattern during the arterial phase; in contrast, during the late phase 11 (73%) of 15 vp(+) nodules showed hypoechoic change with spotty signals. This difference is statistically significant (P < 0.0001) when compared with a high incidence (52%) of signal defect in the vp(–) group. The existence of well-differentiated components associated with the periphery of moderately differentiated HCCs also correlated closely with patterns during the late phase (P < 0.01).Conclusions Late-phase contrast-enhanced US images of small HCCs with a galactose-based contrast agent are useful for predicting specific histologic characteristics. 相似文献
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相干对比成像技术评价心肌活性标准的确立 总被引:2,自引:1,他引:1
目的 以正电子发射断层摄影 (PET)为标准 ,探讨相干对比成像 (CCI)技术评价心肌活性的可行性 ,并确定相干对比成像(CCI)技术判定心肌活性的标准。方法 31例前壁 AMI患者在经皮冠脉介入梗死相关动脉 (IRA)重建后 3个月利用 CCI技术行实时静脉心肌声学造影(MCE) ,评价心肌灌注和运动 ;同时进行 PET检查。结果 在 4 6 4个节段中 ,PET检出 195个存活心肌节段和 2 6 9个非存活心肌节段。以 PET为金标准 ,确定 CCI判断心肌活性标准为 :若室壁运动评分 (MCES)≤ 2 ,心肌声学造影 (VWMS)≤ 2 ,可判定为存活心肌 ;若 MCES=3,VWMS≥ 3,可判定为非存活心肌 ;存活心肌与非存活心肌的标化 A· β值的分界值 (cutoff value)为 0 .2 3;CCI检测存活心肌的敏感性、特异性和精确性分别为 80 %、 95 .5 %和 89% ;K系数检验表明 ,CCI检测结果与 PET检查结果的吻合度较强 (K=0 .770 ,P=0 .0 0 0 1)。结论 CCI技术是一种价廉、可靠易行的评价心肌活性的新的无创方法 ,其评估心肌活性的敏感性、特异性和精确性均较高。 相似文献
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L. Vlahos M.D. A. Gouliamos W. Clauss A. Kalovidouris A. Athanasopoulou A. Petroulakis A. Hadjiioannou C. Papavasiliou 《Abdominal imaging》1992,17(1):300-304
Thirty-one patients were investigated with magnetic resonance (MR) imaging of the lower abdomen before and after the administration of gadopentetate dimeglumine (Gd-DTPA) solution per os or per rectum or from both routes for the opacification of the intestinal tract. The parameters evaluated were: (a) contrast medium distribution, (b) degree of filling of the bowel lumen, (c) contrast between the bowel lumen and the surrounding normal or pathological structures, and (d) whether the administration of the contrast agent improved the diagnostic ability of MR compared to computed tomography (CT) or plain MR of the same region. Gd-DTPA, at a concentration of 1 mmol/L, produced a positive signal irrespective of its dilution in the bowel and good contrast between the bowel lumen and the adjacent tissues or any possible pathological lesions. From the diagnostic point of view, after the administration of contrast medium, MR is comparable to CT and much superior to plain MR. It is concluded that opacification of the bowel with Gd-DTPA solution will improve the diagnostic yield of MR imaging of the lower abdomen. 相似文献
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Satoshi Yamada Kaoru Komuro Mariko Taniguchi Ayumi Uranishi Hiroshi Komatsu Toshihiko Asanuma Fuminobu Ishikura Hisao Onozuka Taisei Mikami Hiroyuki Tsutsui Shintaro Beppu 《Journal of Medical Ultrasonics》2006,33(2):77-83
Purpose In high mechanical index (MI) contrast ultrasonography it has been shown that the power of contrast signal intensity (CI)
has a strong linear correlation with the concentration of the ultrasound contrast agent under conditions of constant applied
acoustic pressure. However, it is unclear whether the linearity is preserved in low-MI contrast ultrasonography. Thus, we
investigated the relationship between ultrasound contrast concentration and CI in vitro.
Methods Solutions of the ultrasound contrast agents Definity and Imagent were prepared at concentrations of 0.5, 2, 8, 32, and 128 μl/l.
Placing a jelly block between the transducer and the solution, the solutions were transmitted using pulse subtraction imaging
with an MI of 0.05, 0.1, and 0.5. CI was measured in dB in a region of interest 3 mm in height placed just below the border
between the jelly and the solution. Data were plotted using double logarithm scales, where the concentration was expressed
in dB as 10 × log (concentration).
Results CI in dB had a strong linear correlation with concentration in dB for both agents with any MI. Best fitted slopes were close
to 1, indicating that the power of CI is proportional to the concentration.
Conclusions In low-MI contrast ultrasonography, the power of CI is proportional to contrast concentration, and CI in dB is logarithmic
to the concentration. Thus, the microbubble concentration can be quantitatively measured even in low-MI contrast ultrasonography. 相似文献
13.
制备结合链酶亲和素超声造影剂的实验研究 总被引:1,自引:0,他引:1
目的:探索制备一种结合链酶亲和素的脂膜超声微泡,以适用于亲和素-生物素法制备靶向超声造影剂,并评价其理化性质。方法:分4组于机械或超声振荡之前或之后,加入链酶亲和素完成超声造影剂的制备,采用浮选法洗涤。观察并检测洗涤前后各组微泡大小、形态、浓度、荧光亮度、微泡与链酶亲和素的结合情况。结果:机械或超声振荡制备的各组结合链酶亲和素的超声造影剂其浓度、形态与普通微泡比较无明显差异,但易静置分层。超声振荡法制备的微泡粒径稍大、浓度偏低。荧光显微镜观察:洗涤前各种不同方法所制备的微泡均能激发出明亮的红色荧光;洗涤后微泡浓度由1010左右降到107左右,微泡荧光亮度仍为“3级”。微泡与链酶亲和素的结合率,各种制备方法间比较差异无显著性意义(P>0.05),其结合率高达98%以上。结论:机械和超声振荡均可制备结合链酶亲和素的负电荷超声造影剂,微泡与其结合率高,为完成亲和素-生物素法制备靶向超声造影剂提供了重要基础。 相似文献
14.
自制脂质体造影剂对正常兔肝脏增强显影的早期实验研究 总被引:7,自引:2,他引:7
目的:探讨自制的脂质体造影剂对肝实的增强显像作用。方法:10只健康家兔经耳缘静脉团注0.01ml/kg的自制脂质体造影剂,测量造影前后肝实质及下腔静脉二维超声图像的灰阶值,并描记出肝实质显像的时间一强度曲线。结果:自制的脂质体造影剂能使肝实质显像明显增强,且增强时间长,高峰持续时间长达50分钟。结论:自制的脂质体造影剂能长时间显著增强肝脏的实质显像,其机理值得进一步研究。 相似文献
15.
目的:使用Meta分析的方法,比较对比增强经颅多普勒超声(c-TCD)与对比增强经胸超声心动图(c-TTE)对卵圆孔未闭(PFO)右向左分流(RLS)的诊断价值。方法:检索PubMed、Web of Science、Embase、Cochrane Library CNKI、VIP、WanFang Data及CBM数据库等自建库至2021年7月3日的文献,采用统计学软件Stata15.1和RevMan5.0进行数据统计分析。结果:共检索出766篇文献,确定纳入38篇文献。Meta分析结果显示,c-TCD的合并敏感度(0.96,95%CI 0.93~0.98)高于c-TTE(0.91,95%CI 0.82~0.96),有显著性差异(Z=2.664,P=0.008);c-TCD的合并特异度(0.93,95%CI 0.86~0.97)低于c-TTE(0.95,95%CI 0.90~0.97),差异无统计学意义(Z=0.481,P=0.630);c-TCD的合并DOR(DOR=384,95%CI 156~943)和c-TTE(DOR=180,95%CI 78~415)之间差异无统计学意义(Z=0... 相似文献
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Acoustically activated submicron droplets of liquid perfluorocarbon are investigated as a new class of ultrasound contrast agent. In the liquid state, intravascular droplets can extravasate within tumours. Activation is then accomplished by using bursts of ultrasound to vaporize the droplets. We use acoustical and optical techniques to assess the characteristics of vaporized droplets and the resulting microbubbles in vitro, including size, conversion threshold, echogenicity and nonlinearity. Under exposure to single 5-50 cycle bursts of ultrasound at 7.5 MHz and mechanical index <1.0, droplets with mean diameter of 400 nm convert into microbubbles with mean diameter of 1.4 μm at 1 ms after vaporization, expanding to 5.6 μm by 1 s. The growth of microbubbles produced by vaporization causes a characteristic time-dependent increase in linear and nonlinear echogenicity, enabling selective detection with conventional bubble-specific imaging. These results suggest that submicron perfluorocarbon droplets, activated in situ, may be a candidate for an extravascular ultrasound contrast agent. 相似文献
17.
GE各系列CT机主要性能指标的实验研究 总被引:1,自引:0,他引:1
目的:探讨GE各系列CT机主要性能指标的实验研究。方法:CT机质量控制检测是CT机应用中的重要环节,笔者采用Victoreen公司生产的AAPM体模,4000M^ 剂量仪及10cm笔型电离室对GT各系列17例CT机的十项主要性能指标进行了检测。结果:标准算法下10种低档CT的空间分辨率为1.0mm,7种中高档机型可达0.75mm,高分辨率算法下,LightspeedQx/I型可达0.4mm,而8800型却只有0.75mm,所抽检的全部CT其密度分辨率均在0.6%,3.5mm以内,最好的可小于2.5mm。结论:高档CT质量优于普通CT主要表现为,更高的空间分辨率,密度分辨率及轴向分辨率,更快的扫描速度,更多的扫描层数,以及功能更丰富的重要软件。 相似文献
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Toshiko Hirai SISUM Hajime Ohishi SJSUM Etsuko Tokuno Miho Takahashi Hiroshi Sakaguchi Hiroshi Anai Yuko Nishimoto Shinji Hirohashi Kimihiko Kichikawa 《Journal of Medical Ultrasonics》2002,29(1):3-9
We attempted to evaluate diagnosis and characterization and to access therapeutic effects in cases of hepatocellular carcinoma
(HCC) by contrast enhanced ultrasound (CEUS) using Coded Harmonic Angio (CHA) with Levovist, an intravenous ultrasound contrast
agent. Fifty-seven HCC foci in 39 patients, including 37 HCC foci in 28 patients before and after transcatheter arterial chemoembolization
or radio frequency ablation, were examined by CEUS using the CHA mode, which is under development. This mode uses digitally
encoded pulse sequences that identify and suppress nonmoving tissue signals and enhance contrast signals from Levovist in
a gray-scale format. In all cases, abundant tortuous intratumoral blood flow was visualized in the early vascular phase by
continuous transmission, while tumor stain was recognized by consecutive 1-to-2 second intermittent transmission. Residual
tumor area after treatment was also clearly depicted by intratumoral blood flow and partial enhancement. CEUS using CHA with
Levovist is likely to become important in the qualitative diagnosis of hepatic tumor and to improve the efficacy of treatment
for HCC. 相似文献
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Vít Herynek Zuzana Berková Eva Dovolilová Daniel Jirák Jan Kříž Peter Girman František Saudek Milan Hájek 《CONTRAST MEDIA & MOLECULAR IMAGING》2011,6(4):308-313
The transplantation of pancreatic islets containing β‐cells, which produce insulin, is an alternative approach to the treatment of type 1 diabetes mellitus. The non‐invasive visualization of transplanted islets can be performed using MRI; however, this requires labeling of the islets with a suitable contrast agent prior to transplantation. The detection of islets labeled by iron oxide‐based contrast agents and transplanted into the liver tissue can be significantly improved using the intravenous administration of a suitable gadolinium contrast agent prior to MRI. The applied contrast agent not only improves the contrast‐to‐noise ratio, but also eliminates artifacts that may lead to an overestimation of the number of hypointense spots and their area; thus it improves the accuracy of automated and semi‐automated procedures used for transplanted islet segmentation and quantification. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献